If a polyp is found with any diagnostic modality, it must be removed and later tested in the pathology laboratory for signs of colorectal cancer. Polyps are routinely removed at the time of colonoscopy via suction aspiration via the suction channel of the scope. These are recovered in a polyp trap bottle. If unable to be aspirated, the large polyp is frequently suctioned to the end of the scope. The entire endoscope is withdrawn to remove the large polyp or it is recovered in a basket fed through the instrument channel. When a treatment tool such as a forcep or snare is inserted into a body channel through an instrument channel of an endoscope, the operator typically must perform the operation while holding the endoscope and treatment tool in their own hands while the treatment tool is being fed to the location in the lumen via the instrument channel. To avoid the intensive labor involved in the extraction and insertion of the treatment tool, Okada (U.S. Pat. No. 7,582,054, issued Sep. 1, 2009) teaches an extraction-insertion system which carries out feeding into or drawing out of a treatment tool through the instrument channel and a driving section that drives this insertion-retraction mechanism. The extraction-insertion system can greatly reduce the time required to insert and retract a snare device after the cauterization and removal of a polyp from the colon which can be as long as 2 meters but there is a need for a device that eliminates the need to retract the endoscope or the polypectomy tool before continuing the examination of the colon for additional polyps. At the discovery of multiple polyps in one site or after a piecemeal polypectomy, the scope must be removed and reinserted after each large polyp or piece is removed. It is an objective of this invention to provide an apparatus for removal of a multiplicity of polyps or pieces thereof without repeated endoscope insertion-retraction operations during the polyp or the piecemeal extraction removal process which is practiced at the present time. Further objectives will become apparent during the detailed discussion of the device of this invention.